Source

The magic of a scorching summer evening

Charlieeeeeee

It's time

do you know where "no beta we die like x" comes from and how it is used?

The term "beta" in this context is short for "beta reader" - a person who reads a fic while it's still in the editing stage and helps the writer get it ready to post. Some betas check grammar. Some check canon compliance. Some are sensitivity readers. There are lots of things that betas can do.

So functionally, saying "no beta" means that the writer didn't get this checked by a second person before they posted it. It's a warning that there might be errors or typos etc. It's mostly used when an author has written something quickly and is posting without doing a lot of (or any) edits first.

As for where it comes from? It all started with a bumper sticker.

This image was an internet meme at one point, and it got meme'd on in the form of "no ___ we ___ like men"

Here on tumblr, one of the versions that got really popular was from now-deleted user @grec1a who created this version:

From there, it migrated to AO3 as the "no beta we die like men" tag, and very often the word men is replaced by the name of a character who dies in canon.